1. Field of the Invention:
The invention relates to preformed, reinforced, ribbed and embossed concrete building panels and, more particularly, to methods of making such concrete building panels.
2. Description of the Prior Art:
Preformed, reinforced concrete panels have previously been utilized in construction of private residences and large commercial buildings. Such concrete panels have been formed in vertical or horizontal molds or forms, some of which molds or forms have contained a decorative pattern. Such decorative patterns impress a complementary pattern on moist concrete placed into the molds or forms. Reinforcing metal material in the form of rods and/or mesh is generally positioned in the molds before the moist concrete is placed in the mold. The moist concrete remains in the mold until hardened and is then separated from the mold.
The preformed concrete panels known in the prior art have not found popularity in the residential building field for a number of reasons. Such prior concrete panels are unduly heavy due to their thickness. Such concrete panels do not have ornamental surface patterns which are appealing to the average home buyer. Further, such concrete panels are not easily utilized in construction of residences because of their weight and the difficulty of attaching interior wall materials and insulation thereto. U.S. Pat. No. 1,525,797 discloses a wall section useable in construction of residences, wherein studs are anchored into a reinforced concrete slab. The resulting concrete panel thus consists of a slab of reinforced concrete having spaced studs anchored therein serving both as reinforcing beams and as nailing strips for attaching interior wall material. However, the anchors extending into the reinforced concrete slab may be severely stressed if the studs become twisted or warped and may expand or contract at a different rate than the concrete. This tends to weaken the concrete slab. Further, the studs which are sufficiently thick to adequately reinforce the concrete slab to which the studs are anchored are quite expensive. The concrete slab portion is thicker than would be necessary if high stresses did not occur at the points at which the studs are anchored to the concrete slab. The exterior of the disclosed concrete building panel is unpatterned, so that either siding or stucco must be applied thereto to provide an attractive finish. The method (disclosed in the above mentioned patent) of making the concrete panels by burying the pre-positioned studs in sand with anchors extending upwardly and placing reinforcing metal mesh and moist aggregate over the sand mold area is archaic and unsuitable for producing low cost concrete building panels. U.S. Pat. Nos. 1,627,171, 2,642,645, 1,211,953, 1,523,628, 1,228,353 and 900,778 were uncovered in a novelty search directed to concrete bulding walls and panels, but are deemed less relevant than the first mentioned patent and will not be discussed in detail.
Various methods of embossing surfaces of moist concrete other than by providing patterns on molds into which the moist concrete is poured are known. Some of the methods involve the use of patterned rollers which are rolled over the surface of the moist concrete to impress a complementary pattern therein. U.S. Pat. No. 3,910,711 discloses a tractor-like device utilizing a bladed roller defining a pattern. The tractor-like device is driven over the moist concrete. A plastic film is dispensed over the surface of the moist concrete and the bladed roller rolls over the plastic film, which is then lifted. The plastic film prevents the moist concrete from sticking to the blades of the roller. The disclosed apparatus and method disclosed in the foregoing patent are suitable for patterning thick, poured-in-place concrete slabs, but are not at all suitable for patterning thin reinforced concrete building panels which are formed in horizontal molds. The weight of the tractor-like device and the difficulties that would be involved in driving it over molds for forming building panels would be totally impractical.
U.S. Pat. Nos. 1,283,770, 2,154,940, 3,801,211, 2,152,264, 551,205, 680,051 and 534,071 disclose various devices utilizing patterned rollers to produce patterns on various materials, but are deemed less relevant than U.S. Pat. No. 3,910,711 to the invention disclosed in the present application.
Accordingly, it is an object of the invention to provide a low cost reinforced concrete building panel and method.
It is another object of the invention to provide a low cost reinforced concrete building panel and method providing an attractive patterned outer surface.
It is yet another object of the invention to provide a low cost reinforced concrete building panel which is readily compatible with residential construction techniques.
Still another object of the invention is to provide a lightweight reinforced concrete building panel which is sufficiently rigid for use in residential construction.
A further object of the invention is to provide an economical method of embossing various patterns on surfaces of concrete building panels during the manufacture of the concrete building panels.
A still further object of the invention is to provide a method of embossing patterns which have an appearance similar to pre-existing walls constructed utilizing conventional building techniques.